64 (number)

List of numbers — Integers << 60 61 62 63 64 65 66 67 68 69 >>
Cardinal	sixty-four
Ordinal	64th (sixty-fourth)
Numeral system
Factorization
Divisors	2, 4, 8, 16, 32
Roman numeral	LXIV
Binary	1000000
Hexadecimal	40

Sixty-four is the square of 8. It is the lowest positive power of two that's surrounded by neither a Mersenne prime nor a Fermat prime. It is also a dodecagonal number.

Sixty-four is also:

• The atomic number of gadolinium, a lanthanide.
• In some computer programming languages, the size in bits of certain data types.
• In chess, the total number of black and white squares on the board.
• The code for international direct dial calls to New Zealand.
• The designation of US Interstate 64, a freeway from Missouri to Virginia.
• The subject of the Beatles song When I'm Sixty-Four
• The registry of the U.S. Navy's aircraft carrier USS Constellation (CV-64)
• The number of Braille characters in the old 6-dot system.
• The year AD 64, 64 BC, or 1964.